Curated cron expression
Every 3 Minutes Cron Expression: */3 * * * *
*/3 * * * * — high-frequency polling — cost and overlap warnings included.
Meaning at a glance
*/3 * * * *
Run every three minutes
20 runs per hour at minutes divisible by 3.
Next-run example: At 10:07, next runs are 10:09, 10:12, 10:15.
How */3 * * * * works
Twenty runs per hour; validate infrastructure cost before deploy.
GitHub Actions minimum is five minutes — not supported there.
Preview next runs and platform conversions in CronWizard before deploying to production.
| Field | Value | Meaning |
|---|---|---|
| Minute | */3 | Configured as */3 |
| Hour | * | Every value |
| Day of month | * | Every value |
| Month | * | Every value |
| Day of week | * | Every value |
Good use cases
- Dev-only polling
- High-frequency metrics (use with care)
Timezone and daylight-saving behavior
Cadence is timezone-neutral.
Use idempotency keys for high frequency.
The expression does not contain a timezone. The scheduler supplies that context. Use the next-run preview above in the same IANA timezone as production, then confirm the target platform's own timezone rules.
Platform compatibility and converted expressions
The source expression is five-field Unix cron. Use the exact equivalent below rather than adding or removing fields by sight.
| Platform | Status | Expression | What to know |
|---|---|---|---|
| Unix crontab | Ready | */3 * * * * | Use directly in a normal five-field user crontab. |
| Kubernetes CronJob | Ready | */3 * * * * | Use as spec.schedule; set spec.timeZone when local wall-clock behavior matters. |
| GitHub Actions | Unsupported | */3 * * * * | Minimum interval is five minutes. |
| Vercel Cron Jobs | Plan / behavior limit | */3 * * * * | Hobby plan allows only daily cron. |
| AWS EventBridge Scheduler | Convert | cron(*/3 * ? * ? *) | Convert to AWS minute-first cron(...), add the required year, and use ? in one day field. |
| Spring @Scheduled | Convert | 0 */3 * * * * | Use Spring’s six fields by prepending seconds and set zone explicitly when needed. |
| systemd timer | Convert | */3 * * * * | Use OnCalendar syntax and validate it with systemd-analyze calendar on the target host. |
Edge cases to check before deployment
- GitHub Actions unsupported.
- Vercel Hobby daily-only.
Frequently asked questions
What does the cron expression */3 * * * * mean?
*/3 * * * * means “run every three minutes.” 20 runs per hour at minutes divisible by 3.
What are the next run times for */3 * * * *?
At 10:07, next runs are 10:09, 10:12, 10:15. Exact timestamps depend on the scheduler timezone and the current time.
What timezone does */3 * * * * use?
Cadence is timezone-neutral.
Can I use */3 * * * * on every scheduling platform?
No. It is a five-field Unix expression. Some platforms accept it directly, while AWS EventBridge Scheduler, Spring, and systemd require the converted form shown in the compatibility table.